The present invention generally relates to a seal between communicating members. More particularly, the present invention relates to a structure forming a sealable fluid-medium connection having a geometry which provides improved sealing at high fluid pressures.
A highly pressurized fluid system is demanding on seals between joined members, such as conduit members in sealed fluid communication with each other. For example, in a fuel injection system for a diesel engine, fuel pressures are often around 30,000 psig, requiring high strength components and seals.
A high-pressure fuel injection system can have a fluid pressure sensor which provides a useable output signal corresponding to fuel pressure in a fuel pump accumulator. The output signal may be directed to an engine control processor. Such a fuel pressure sensor may be mounted to a port in a wall of the accumulator.
A need exists for a structure providing a reliable seal connection in a system carrying or containing fluids at high pressures, such as a connection for a pressure sensor in a fuel injection system.
Conventionally, high-pressure seals have threaded connections which are tightenable to increase compressive loads on a deformable seal disc or ring located between connected members. In order to obtain an adequate sealing compression, previous connectors required tightening to a certain precise torque, and sometimes a very high torque. Depending on the connector design and the particular seal material subjected to high loading, overtightening a conventional seal may cause an uncontrolled plastic deformation and extrusion of the seal material, resulting in load loss and seal failure. Accordingly, a seal design is desired which is forgiving in the amount of torque required, providing adequate sealing within a range of torques, and which reduces the risk of causing seal failure by overdeformation of the seal material.
Additionally, a seal structure is desirable which minimizes the amount of torque required to set the seal. Such a lower torque would ease assembly during manufacture or repair.